Anchor plug



Patented Oct. 17, 1933 g UNITED STATES PA'rENr oFFlcE y n ANCHORV PLUG Laurence S. Dennis, Los Angeles, Calif. Appliootion March 11, 1932.` serial No. 598,125 2 claims. (o1. 'l2-105) This invention relates broadly to the art 'of manufacturing anchoring plugs of the character commonly inserted in the walls of buildings which are composed of concrete, brick, stone, stucco, plaster, buttonlath and the like to provide a suitable anchorage or holding means for screwsV or theY like whereby articles of various sorts may be conveniently and safely applied to the wall.

e Wall plugs at the present time which are used for this purpose consist largely of fibrous material adhesively joined together. Y

Sometimes the fibrous strands .are twisted and spirally wound upon a core of weaker construction than the strands themselves, and sometimes the fibrous strands are arranged in parallel formation and have a solid core less rm than the outer portion thereof.

In either type, it is usually the object to have the fibrous strands either weakly held together or the core made less firm than its outer wall whereby the screw Vmay easily thread into the matter in which it is inserted.

It is to be understood, however, there are some plugs now on the market which have no core at all and are provided with an axial aperture running completely lengthwise of theplug.

The drawbacks and disadvantages of the present-day plugs almost prohibit their use. TheyY are whatV their construction implies weakly held together. Plugs of this type rupture along their adhesively united surfaces. They dry and subsequently crumble under the force of impact required to insert or extract the screw. VIn these plugs heretofore used the bond furnished by the plug is weak both longitudinally and transversely and the key hold quality of ,the device is lacking. lThe threads of the screw cut the fibrous 'strandsgof the plug causing their rupture whereby the holding power of a number of threads on a screw is rendered practically nil. When subjected to changes in temperature such devices contract and' crack and when once used are rendered incapable of functioning as an anchor the second time. i

Animportant objectof the invention is the selection of a natural commodity which, upon being treated, will lpossess the necessary attributes'essential in an anchor or Wall plug of the character hereinafter more fully set forth, and thereby eliminating the disadvantages which would otherwise occur in the manufacture of the device.

A further object of the invention is to provide a natural growth of wood adapted for use into.

in different types of building construction as has been previously mentioned which, when` a screw'isl screwed thereinto, will cause an' even distribution of girth expansion against the wall of the hole into which the plug has been inserted.

Such a plug may properly be termed an expansion plug since the cellular Wall or pithy construction of the plug after treatment has greater' expanding qualities than anything heretofore used for the same purpose and will not go to pieces under stress of expansion or impact due to hammering, also possessing a certain degree of resiliency which will enable it to be used again because of its tough quality.

A still further object is to provide a wood which when treated by impregnation will not deteriorate nor decay and will not be Vaffected by climatic conditions.

Still further advantages reside in the peculiar novelty of shaping the plug whereby a greater holding power of the screw is assured. Such a specimen of plug and its adaptation is shown inthe accompanying drawing, in which:

Fig. 1 is an end view of the plug.

Fig. 2 is a side view of the plug.

Fig. 3 is a fragmentary section of a wall illustrating the manner in which the plug would normally appear in section after it is inserted in the wall and aV holding screw is screwed there- The plug is out from peeled rattan wood, commonly known as wicker, into standard sizes and lengths. The sizes are reckoned according to the standard sizes of screws which they take. l

The product is imported into this country in bundles which are made up of uniform sizes and lengths. From this material the plugs are cut to certain standard lengths and shaped down to the proper size for the plugs. They are afterwards longitudinally grooved and bored'for correspond- 95 ing sizes of screws and then subjected to a creosote bath. The diameter of the peeled rattan needsbut little dressing down.

Referring particularly to the drawing, it will be noted the wicker specimen plug 1 is composed 100 of a multitude of cells 2. The cells are uniformly distributed throughout the cross section of the plug, as may be seen by referring to Fig. 2. They run longitudinally through .the plug and the walls of the cells are made ofiiber which also runs longitudinally of the plug. This fiber is very tough.

The walls of the plug are longitudinally grooved as indicated by the numeral 3. The function of the grooves is to permit of girth oompressibiniy whereby when the tapered end 4 of the plug is inserted into the hole 5 of the wall 6, the walls of the groove may yield transversely thus diminishing the normal diameter of the plug so that when the plug is completely inserted it will have the appearance as shown in Fig. 3, and the peripheral surface of the plug will thereby maintain a firm grip with the wall 6 to prevent twisting when the screw '7 is Screwed into the plug, as for eaniple, for holdingr the bracket 8 in place.

The grooves are also adapted to house nails or plugs which may be driven into the wall alongside the plug when a firmer contact with the plug and wall is desired. Said grooves are further adapted for the accumulation of grit or dust particles which ordinarily abounds in a hole.

Into the plug part way is drilled a central hole 9 of lesser diameter and length than the screw which is to be inserted therein. The hole forms a guide for the screw. The hole is expanded to the diameter of the screw upon insertion and the fibers of the plug yield to the' pressure of the lthreads of the screw as shown in Fig. 3 thus affording a grippage with the' screw threads without rupturing the adjacent iibers.

The hole 9 is made shorter than the screw in lorder toprovide stock at the end of the screw for ypower to a screw anchor.

After the wicker is cut into plugsgrooved and bored it is subjected to a chemical treatment vwhereby the plug is preserved from drying out completely and losing its resiliency. The treatment towhich the plug is subjected gives to it resiliency and sustains it. 'This treatment lls the minute longitudinal capillaries with the preserving substance. After being treated with creosote the longitudinally extending iibers are better capacitated for resisting lateral distortion without breaking. Creosote is also alubricant.

. After the screw has once been inserted a threadedsocket is formed for the vscrew which permits removal and insertion oi the screw without damaging the internal threads of the plug. The creosote' prevents the screw from becoming yrust tight.

` These plugs may vary in size, principally from 5% to /E," in'diaineter and from l to 3 in ga creosote bath and allowing it to remain there until it is thoroughly impregnated. The plug is afterwards dipped in an aniline dye solution Ywhich gives to the plug a coating whereby the 4creosote is sealed within the plug.

This dye coating also gives to the plug a suitable nish and clean and neat appearance. It further affords additional'protection for the plug, conserving vthe lubricating qualities and elastic effect afforded by the creosote. Another advantage secured by applying the aniline coating over the creosote is in the production of a cleaner article to handle.

This method of treating wicker whereby the multitude'of naturally formed longitudinal holes are filled is not only beneficial as a preservative which is capable of protecting the tissue, not only against decay or against the attack of many parasites to which it is exposed, but also the improved effect produced from a mechanical point of view.

The chemical properties of creosote tend to retain a softening of the fibrous strands whereby they may be elastically stiained without rupture where contacted with a screw thread and without causing the plug to crumble or go to pieces under the force of impact.

When slightly yheated the consistency of the creosote is such that it is easily injected into all parts of the wicker, and when it solidies in the pores it is impossiblefor it to drain or exude from the pores. The composition of creosote is'such that not only germs, but also their spores, are

rrendered inactive in the shortest possible time.

The particular selection of this type of wicker plug whereby the expensive steps of manufacture are eliminated, and' the method of treating the plug with a substance such as creosote produces in the plug both a chemical and mechanical effect as hereinbefore set forth and is considered Van advanced step in the art of producing screw anchors or wall plugs.

The means for accomplishing the grooving, the boring or shaping of the plug is not considered, per se, a part of the present invention. Such a particular machine, however, may be made the subject matter'of other applications for Letters Patent to follow.

I claim:

1. As an article of manufacture, an anchor plug made from peeled rattan, said plug being of a woody nature and having naturally formed longitudinally extending cells and fibers, said cells beingimpregnated with a substance whereby the nbers of the plug are rendered elastic, there being an axial bore which extends into one end of the plug, the length of said bore being lessthan the length of the screw to be screwed thereinto, said `fibers yielding to the threads of the screw without rupture, whereby when thevscrew is rmly screwed within the plug, a threaded socket conforming to the size of the `screw is permanently molded within the plug.

2. An anchoring device consisting of a rattan plug having naturally formed, longitudinally extending cells and fibers, said cells being impregnated with a substance whereby the fibers of the plug are rendered elastic, there being an`axial bore which extends into the plug a considerably lless distance than its length, a screwwofgreater length and greater diameter than said bore screwed thereinto thus causing the threads Vof the screw to imbed themselves in the walls ofthe bore and the point of the screw to penetrate below the depth of the bore, the headed portion of the screw projecting beyond the outer end of the plug thereby forming a suitable support for a bracket or hanger.

LAURENCE S. DENNIS. 

